Is Musical Auditory Stimulation Able to Influence the Recovery of Autonomic Modulation After Exercise?

Context: The effects of musical auditory stimulation on the human body have received considerable interest, especially when related to health and wellbeing, so the objective was to verify the influence of classical music exposure on autonomic modulation in recovery after exercise. Methods: 35 healthy young men aged 21.74 ± 2.59 years were evaluated. Volunteers perform 2-day evaluations, 1 day without musical stimulus and 1 with musical stimulation through classical music during exercise and recovery. Physical exercises were performed on a treadmill with an intensity of 6.0 km/hr + 1% of inclination in the first 5 minutes for physical "warm-up", followed by 25 minutes with an intensity equivalent to 60% of the maximum velocity (Vmax), with a same slope according to the Conconi's threshold. Finally, the volunteers remain at rest for 60 minutes for recovery. Heart rate variability (HRV) was analyzed in some moments of recovery by linear (RMSSD, SDNN, LF and HF (milliseconds squared and normalized unit) and LF/HF ratio, RRtri, TINN and the Poincaré plot: SD1, SD2 and SD1/SD2) and nonlinear indexes (DFA Total, DFA Alpha 1 and Symbolic Analysis: Shannon's Entropy, 0V%, 1V%, 2LV% and 2ULV%). Results: No differences were found in the comparison between the values of the HRV indexes between protocols and interaction moments vs protocols. Differences were observed between the moments for most indexes (P < .05). Conclusions: Classical music did not significantly influence the autonomic control of heart rate in the recovery phase after submaximal exercise.

The Combined Relationship of Vitamin D and Weight-Bearing Sports Participation on Areal Bone Density and Geometry Among Adolescents: ABCD - Growth Study.

Osteoporosis is a public health problem, which negatively impacts society and national health services worldwide. Altered mineralization of the skeleton can be caused by persistent vitamin D deficiency. However, the combined impact of both on bone health is still under investigation. In fact, although there is compelling evidence in the literature about the positive effect of weight-bearing sports participation on bone mineral density, its impact on bone geometry gains more attention in pediatric population. The sports modalities that we evaluated were artistic gymnastics and track and field. Nonsports group was composed of 43 adolescents. Bone density was assessed using dual-energy X-ray absorptiometry. Vitamin D concentration was assessed by blood analysis. In the crude comparison of bone outcomes, the sport group presented higher aBMD only in the trochanter (p-value = 0.040). Considering the combination of the engagement in sports and vitamin D, adolescents in the sports group presented significantly higher values of aBMD in lower limbs, whole body, trochanter, shaft, and femur whole body (p-value = 0.024, 0.035, 0.001, 0.019 and 0.003 respectly). In contrast, only the sport group with high vitamin D presented a higher CSA (p-value = 0.015) and femur neck aBMD compared to the non-sport/low vitamin D group. Only adolescents with a combination of sports participation and higher serum concentrations of vitamin D presented better bone geometry, denoting the relevance of the combination of both factors to bone health.

Low Occurrence of Musculoskeletal Symptoms in Swimming? Musculoskeletal Symptoms and Sports Participation in Adolescents: Cross Sectional Study (ABCD-Growth Study).

The purpose of this paper was to identify the association between the occurrence of musculoskeletal symptoms (MS) and sports participation in adolescents. The sample included 193 adolescents (11 to 17 years of age; 131 boys and 62 girls). For this cross-sectional study, participants were categorized into four groups: "no-sports", "repetitive non-impact sports", "high-impact sports", and "odd-impact sports". A questionnaire was used, which defined MS as pain or any musculoskeletal complaint that led to restriction of current normal activities. In the entire sample, 112 adolescents reported at least one episode of MS during the recording, representing 58% of the sample. Our findings highlight that adolescents regularly engaged in odd-impact sports, such as martial arts, report a higher occurrence of MS than swimmers and adolescents who do not participate in any physical activity.

More than Sports Participation: The Role of Ground Reaction Force, Osteocalcin and Lean Soft Tissue on Bone Density Accrual in Adolescents: ABCD Growth Study.

The objective of this study was to identify predictors of 12-mo areal bone density accrual in different body segments, lean soft tissue, and osteogenic characteristics attributed to sports participation among adolescent girls and boys. Adolescents (Girls [n = 64], [aged = 14.7]); Boys [n = 129], [aged = 14.6]) were stratified into three groups according to their engagement in different sports (Control [n = 68], Swimming [n = 25], and Weight-bearing sports [n = 100]). Areal bone density (aBMD [g/cm²]) and lean soft tissue (LST) [kg] were measured by dual-energy x-ray absorptiometry (DXA; Lunar DPX-NT; General Electric Healthcare, Little Chalfont, Buckinghamshire, United Kingdom). The ground reaction force (GRF) index attributed to sports participation (Sport-GRF) was created considering the GRF attributed to each sport, body weight of the adolescent, and the amount of time spent in sports participation. Osteocalcin levels (ng/mL) were estimated from a venous blood sample. Multiple regression analysis showed that after adjusting for covariates, the models involving sport-GRF, LST (Δ), and osteocalcin explained 15.8% to 76.2% of the aBMD gains. Specifically in girls, OC was only associated with lower limb aBMD accrual. In boys, however, sport ground reaction forces were positively associated with total spine aBMD accrual. Furthermore, the LST (Δ) was positively associated with aBMD accrual in all body sites (ß = 0.003 to 0.011) in both sexes. Increases in LST contributed significantly to gains in aBMD accrual in both sexes, being a more important predictor of changes in bone outcomes than ground reaction forces and osteocalcin.

Genetic variability in COVID-19-related genes in the Brazilian population

SARS-CoV-2 employs the angiotensin-converting enzyme 2 (ACE2) receptor and the transmembrane serine protease (TMPRSS2) to infect human lung cells. Previous studies have suggested that different host genetic backgrounds in ACE2 and TMPRSS2 could contribute to differences in the rate of infection or severity of COVID-19. Recent studies also showed that variants in 15 genes related to type I interferon immunity to influenza virus could predispose to life-threatening COVID-19 pneumonia. Additional genes (SLC6A20, LZTFL1, CCR9, FYCO1, CXCR6, XCR1, IL6, CTSL, ABO, and FURIN) and HLA alleles have also been implicated in response to infection with SARS-CoV-2. Currently, Brazil has recorded the third-highest number of COVID-19 patients worldwide. We aim to investigate the genetic variation present in COVID-19-related genes in the Brazilian population. We analysed 27 candidate genes and HLA alleles in 954 admixed Brazilian exomes. We used the information available in two public databases (http://www.bipmed.org and http://abraom.ib.usp.br/), and additional exomes from individuals born in southeast Brazil, the region with the highest number of COVID-19 patients in the country. Variant allele frequencies were compared with the 1000 Genomes Project phase 3 (1KGP) and the gnomAD databases. We found 395 non-synonymous variants; of these, 325 were also found in the 1000 Genome Project phase 3 (1KGP) and/or gnomAD. Six of these variants were previously reported as putatively influencing the rate of infection or clinical prognosis for COVID-19. The remaining 70 variants were identified exclusively in the Brazilian sample, with a mean allele frequency of 0.0025. In silico prediction of the impact in protein function revealed that three of these rare variants were pathogenic. Furthermore, we identified HLA alleles that were previously associated with COVID-19 response at loci DQB1 and DRB1. Our results showed genetic variability common to other populations, but also rare and ultra-rare variants exclusively found in the Brazilian population. These findings could potentially lead to differences in the rate of infection or response to infection by SARS-CoV-2 and should be further investigated in patients with the disease.

Influential role of lean soft tissue in the association between training volume and bone mineral density among male adolescent practitioners of impact-loading sports: ABCD Growth study.

BACKGROUND: Training volume is associated with direct and indirect pathways of bone adaptations. In addition, training volume is a training variable associated with lean soft tissue (LST), which has been shown to be an important predictor of areal bone mineral density (aBMD). Thus, the aim of this study is to investigate the influential role of lean soft tissue (LST) in the association between training volume and aBMD in male adolescent athletes. METHODS: This cross-sectional study was composed of 299 male adolescent athletes, mean age 14.1 (1.8) years, from 9 different weight-bearing modalities. The Ethical Board approved the investigation. The adolescents reported the number of days per week they trained and the time spent training and, from this, the training volume (h/wk) was estimated. The LST and aBMD were assessed by dual-energy x-ray absorptiometry. Somatic maturation was estimated by the peak of height velocity. Mediation analysis was performed to investigate the role of LST in the association between training volume and aBMD. Level of significance was set at p < 0.05. RESULTS: LST partially explained the association between training volume and aBMD in all body segments: upper limbs (58.37%; ß = 0.00142), lower limbs (28.35%; ß = 0.00156), spine (33.80%; ß = 0.00124), and whole body (41.82%, ß = 0.00131). There was no direct effect of training volume on aBMD in upper limbs (CI -0.00085 to 0.00287). CONCLUSION: The association between training volume and aBMD is influenced by LST in different body segments, mainly upper limbs, demonstrating that interventions aiming to enhance aBMD should also consider LST as an important variable to be managed.

Impact of changes in fat mass and lean soft tissue on bone mineral density accrual in adolescents engaged in different sports: ABCD Growth Study.

Body composition can have a significant impact on bone mineral density (BMD) in pediatric patients and may cause bone disease. This study demonstrated that lean soft tissue (LST) seems to have a greater impact on BMD gain in the lower limbs of adolescents. PURPOSE: To analyze the impact of changes in lean soft tissue (LST) and fat mass on areal bone mineral density (BMD) accrual in the lower limbs among adolescents engaged in sports with different weight-bearing levels. METHODS: Longitudinal (12 months: measurements at two time points). Adolescents of both sexes (n = 191; 62 girls [32.5%] and 129 boys [67.5%]) were divided into three groups: control group (n = 65), swimming group (n = 25), and weight-bearing sports group (n = 100). Absolute changes in LST (kg) and fat mass (kg) were the independent variables, while BMD accrual (left and right legs) was the dependent variable. Linear regression was used to assess the relationship between dependent and independent variables in a multivariate model adjusted by sex, body weight, somatic maturation, serum osteocalcin, and baseline values of BMD of the lower limbs. RESULTS: For the left leg, LST was positively related to areal BMD accrual in the control (ß = 0.021 [95%CI: 0.001 to 0.042]) and weight-bearing sport groups (ß = 0.051 [95%CI: 0.037 to 0.065]), but not among swimmers (ß = 0.029 [95%CI: - 0.004 to 0.062]). For the right leg, LST was positively related to areal BMD accrual in the swimming group (ß = 0.065 [95%CI: 0.031 to 0.100]) and weight-bearing sport groups (ß = 0.048 [95%CI: 0.034 to 0.062]), but not in the control group (ß = 0.014 [95%CI: - 0.002 to 0.030]). Fat mass was not significantly related to areal BMD in either leg. CONCLUSIONS: Changes in LST were the most relevant determinant of BMD accrual in the lower limbs, mainly among adolescents engaged in sports.

Bone Mineral Density and Sports Participation.

The objective of our study was to identify differences in bone mineral density (BMD) according to different sports among adolescents, as well as to identify assessments of relevant mediators. The sample consisted of 429 adolescents with a mean age of 13.3 ± 1.7 yr. The sports modalities that we evaluated were judo, karate, kung fu, swimming, basketball, and soccer. Nonsports group was composed of 111 adolescents. Bone density was assessed using dual-energy X-ray absorptiometry. Regarding BMD values, female engaged in karate had higher BMD values than girls from the no sports group (p = 0.01). Boys engaged in soccer and karate presented the highest BMD values than all the other groups (p = 0.01). The most relevant mediators were the body mass index and lean soft tissue for boys and girls. Different sports presented different results regarding BMD gains, which were influenced by body mass index and whole-body lean soft tissue.

Impact of Artistic Gymnastics on Bone Formation Marker, Density and Geometry in Female Adolescents: ABCD-Growth Study.

BACKGROUND: To compare bone density accrual and markers of bone geometry and formation between female adolescents engaged and not engaged in artistic gymnastics (AGs). METHODS: This was a 12-month longitudinal study involving 20 female adolescents, including 10 controls and 10 gymnasts (AGs) aged 11 to 16 years. At baseline, the gymnasts had a minimum of 12 months of practice, and the controls reported no participation in any organized sport. Bone mineral density (BMD) was measured in the lower limbs, upper limbs, spine, and whole body. In addition, BMD and geometrical properties of the femur were assessed. As a bone formation marker, osteocalcin level was measured. RESULTS: Femoral aspects were increased in the gymnasts by 19% (P=0.009), 14% (P=0.047), and 10% (P=0.046) in the Ward's triangle, trochanter, and the overall bone, respectively, than in the control girls. Geometrical parameters, bone accrual, and osteocalcin levels were similar in both groups. The weekly training load explained 30.8% of all bone gains on the lower limbs and affected the density on parts of the femur. CONCLUSIONS: The gymnasts, after a 12-month follow-up, demonstrated a higher BMD in the Ward's triangle and whole femur than the controls, as well as an improvement in femur density. These changes were mainly due to the weekly training load. Lastly, the gymnasts had significant bone accrual (after 12 months) in the upper limbs, lower limbs, and whole body.

Sports participation and muscle mass affect sex-related differences in bone mineral density between male and female adolescents: A longitudinal study.

BACKGROUND: Sports participation plays an important role in bone gain during childhood and adolescence. The aim here was to identify sex-related determinants of bone mineral density (BMD) differences between male and female adolescents, with emphasis on the role of sports participation. DESIGN AND SETTING: Longitudinal study conducted in a public university in Presidente Prudente, Brazil. METHODS: The sample comprised 48 adolescents aged 11-17 years, of both sexes, who were matched according to sex, age and sports participation. BMD was the main outcome, while muscle mass, sports participation, calendar age and biological maturation were treated as covariates. Participants were followed up after nine months. RESULTS: At baseline, BMD values were similar between the sexes. However, adjustment for covariates showed that BMD was higher among girls at all sites, with a contribution from lean soft tissue (LST) in the model (partial eta-squared, ES-r = 0.619 in upper limbs; 0.643 in lower limbs; 0.699 in spine; and 0.599 in whole body). Sports participation only explained the upper-limb variance (ES-r = 0.99). At the follow-up, the results resembled the baseline except in the lower limbs (P = 0.109), in which BMD was similar between the groups. BMD gain over time was similar between girls and boys in all segments, and baseline LST affected upper-limb and whole-body BMD accrual (ES-r = 0.396 and 0.107, respectively). CONCLUSION: Whole-body and specific-site BMD differed between baseline and follow-up. However,BMD accrual was similar between the sexes, given that muscle mass constituted the most relevant determinant of the difference between them.

Sports Participation Decreases the Incidence of Traumatic, Nonsports-Related Fractures Among Adolescents.

OBJECTIVES: To investigate the effects of different sports on the incidence of traumatic fractures (TF; sport-related fractures and those occurring in daily activities) among adolescents during the 9-month follow-up period. METHODS: The adolescents were contacted in 11 different locations (3 public/private schools and 8 sports clubs), and the final sample was divided into 3 groups: control (n = 121), swimming (n = 51), and impact sports (n = 142). The incidence of TF was calculated by considering the exposure to sports (TF/1000 h). RESULTS: In the overall sample, the incidence of TF was 1.29 TF/1000 hours of sports exposure, while the incidence of sport-related TF was 0.39 TF/1000 hours of sports exposure. Adolescents engaged in sports (P = .004), independently of type (P = .001), for 3 or more days per week (P = .004) and more than 60 minutes per day (P = .001) had lower incidence of TF. Adolescents engaged in more than 300 minutes per week of sport (0.17 TF/1000 h) had lower incidence than those who did not (2.06 TF/1000 h [P = .001]). A similar finding was observed for sport-related TF (≥300 min/wk: 0.08 TF/1000 h vs 300 min/wk: 0.615 TF/1000 h [P = .02]). CONCLUSION: Adolescents engaged in sports showed a lower incidence of TF than nonengaged adolescents.

Impact of Artistic Gymnastics on Bone Formation Marker, Density and Geometry in Female Adolescents: ABCD-Growth Study

BACKGROUND: To compare bone density accrual and markers of bone geometry and formation between female adolescents engaged and not engaged in artistic gymnastics (AGs). METHODS: This was a 12-month longitudinal study involving 20 female adolescents, including 10 controls and 10 gymnasts (AGs) aged 11 to 16 years. At baseline, the gymnasts had a minimum of 12 months of practice, and the controls reported no participation in any organized sport. Bone mineral density (BMD) was measured in the lower limbs, upper limbs, spine, and whole body. In addition, BMD and geometrical properties of the femur were assessed. As a bone formation marker, osteocalcin level was measured. RESULTS: Femoral aspects were increased in the gymnasts by 19% (P=0.009), 14% (P=0.047), and 10% (P=0.046) in the Ward's triangle, trochanter, and the overall bone, respectively, than in the control girls. Geometrical parameters, bone accrual, and osteocalcin levels were similar in both groups. The weekly training load explained 30.8% of all bone gains on the lower limbs and affected the density on parts of the femur. CONCLUSIONS: The gymnasts, after a 12-month follow-up, demonstrated a higher BMD in the Ward's triangle and whole femur than the controls, as well as an improvement in femur density. These changes were mainly due to the weekly training load. Lastly, the gymnasts had significant bone accrual (after 12 months) in the upper limbs, lower limbs, and whole body.

Somatic maturation and the relationship between bone mineral variables and types of sports among adolescents: cross-sectional study.

CONTEXT AND OBJECTIVE:: Peak height velocity (PHV) is an important maturational event during adolescence that affects skeleton size. The objective here was to compare bone variables in adolescents who practiced different types of sports, and to identify whether differences in bone variables attributed to sports practice were dependent on somatic maturation status. DESIGN AND SETTING:: Cross-sectional study, São Paulo State University (UNESP). METHODS:: The study was composed of 93 adolescents (12 to 16.5 years old), divided into three groups: no-sport group (n = 42), soccer/basketball group (n = 26) and swimming group (n = 25). Bone mineral density and content were measured using dual-energy x-ray absorptiometry and somatic maturation was estimated through using peak height velocity. Data on training load were provided by the coaches. RESULTS:: Adolescents whose PHV occurred at an older age presented higher bone mineral density in their upper limbs (P = 0.018). After adjustments for confounders, such as somatic maturation, the swimmers presented lower values for bone mineral density in their lower limbs, spine and whole body. Only the bone mineral density in the upper limbs was similar between the groups. There was a negative relationship between whole-body bone mineral content and the weekly training hours (ß: -1563.967; 95% confidence interval, CI: -2916.484 to -211.450). CONCLUSION:: The differences in bone variables attributed to sport practice occurred independently of maturation, while high training load in situations of hypogravity seemed to be related to lower bone mass in swimmers.

Somatic maturation and the relationship between bone mineral variables and types of sports among adolescents: cross-sectional study / Maturação somática e o relacionamento entre variáveis minerais ósseas e modalidades esportivas em adolescentes: estudo transversal

ABSTRACT CONTEXT AND OBJECTIVE: Peak height velocity (PHV) is an important maturational event during adolescence that affects skeleton size. The objective here was to compare bone variables in adolescents who practiced different types of sports, and to identify whether differences in bone variables attributed to sports practice were dependent on somatic maturation status. DESIGN AND SETTING: Cross-sectional study, São Paulo State University (UNESP). METHODS: The study was composed of 93 adolescents (12 to 16.5 years old), divided into three groups: no-sport group (n = 42), soccer/basketball group (n = 26) and swimming group (n = 25). Bone mineral density and content were measured using dual-energy x-ray absorptiometry and somatic maturation was estimated through using peak height velocity. Data on training load were provided by the coaches. RESULTS: Adolescents whose PHV occurred at an older age presented higher bone mineral density in their upper limbs (P = 0.018). After adjustments for confounders, such as somatic maturation, the swimmers presented lower values for bone mineral density in their lower limbs, spine and whole body. Only the bone mineral density in the upper limbs was similar between the groups. There was a negative relationship between whole-body bone mineral content and the weekly training hours (β: -1563.967; 95% confidence interval, CI: -2916.484 to -211.450). CONCLUSION: The differences in bone variables attributed to sport practice occurred independently of maturation, while high training load in situations of hypogravity seemed to be related to lower bone mass in swimmers.

RESUMO CONTEXTO E OBJETIVO: O pico de velocidade de crescimento (PVC) constitui importante evento maturacional durante a adolescência, afetando o tamanho do esqueleto. O objetivo do estudo foi comparar variáveis ósseas em adolescentes praticantes de diferentes modalidades esportivas, bem como identificar se diferenças nas variáveis ósseas atribuídas à prática esportiva são dependentes do estado da maturação somática. DESENHO E LOCAL: Estudo transversal, Universidade Estadual Paulista (UNESP). MÉTODOS: O estudo foi constituído por 93 adolescentes (12 a 16,5 anos), divididos em três grupos: grupo sem envolvimento esportivo (n = 42), futebol/basquete (n = 26) e natação (n = 25). A densidade e conteúdo mineral ósseo foram mensurados utilizando absortiometria de raio-x de dupla energia e a maturação somática foi estimada através do uso do PVC. Informações sobre volume de treinamento foram fornecidas pelos treinadores. RESULTADOS: Adolescentes com idade tardia no PVC apresentaram maiores valores de densidade mineral óssea em membros superiores (P = 0,018). Após ajustes por variáveis de confusão, como a maturação somática, os nadadores apresentaram menores valores de densidade mineral óssea em membros inferiores, coluna e corpo inteiro. Apenas a densidade mineral óssea de membros superiores foi similar entre os grupos. Existiu relação negativa entre conteúdo mineral ósseo de corpo inteiro e tempo de treino semanal (β: -1563.967; 95% intervalo de confiança, IC: -2916.484 a -211.450). CONCLUSÃO: As diferenças em variáveis ósseas atribuídas à prática esportiva ocorrem independentemente da maturação, enquanto elevada quantidade de treinamento em situações de hipogravidade parece estar relacionada com menor massa óssea em nadadores.

Impact sports and bone fractures among adolescents.

The objective of the present study was to investigate the effects of different sports on stress fractures among adolescents during a 9-month follow-up period. The sample was composed of 184 adolescents divided into three groups (impact sports [n = 102]; swimming [n = 35]; non-sports [n = 47]). The occurrence of stress fracture was reported by participants and coaches. As potential confounders we considered age, sex, resistance training, body composition variables and age at peak of height velocity. There were 13 adolescents who reported fractures during the 9-month period. Bone mineral density values were higher in adolescents engaged in impact sports (P-value = 0.002). Independently of confounders, the risk of stress fracture was lower in adolescents engaged in impact sports than in non-active adolescents (hazard ratio [HR] = 0.23 [95% confidence interval (CI) = 0.05 to 0.98]), while swimming practice was not associated to lower risk of fracture (HR = 0.49 [95% CI = 0.09 to 2.55]). In conclusion, the findings from this study indicate the importance of sports participation among adolescents in the reduction of stress fracture risk, especially with impact sports. More importantly, these results could be relevant for recognising adolescents in danger of not reaching their potential for peak bone mass and later an increased risk of fractures.

Prolonged Practice of Swimming Is Negatively Related to Bone Mineral Density Gains in Adolescents.

BACKGROUND: The practice of swimming in "hypogravity" conditions has potential to decrease bone formation because it decreases the time engaged in weight-bearing activities usually observed in the daily activities of adolescents. Therefore, adolescents competing in national levels would be more exposed to these deleterious effects, because they are engaged in long routines of training during most part of the year. To analyze the effect of swimming on bone mineral density (BMD) gain among adolescents engaged in national level competitions during a 9-month period. METHODS: Fifty-five adolescents; the control group contained 29 adolescents and the swimming group was composed of 26 athletes. During the cohort study, BMD, body fat (BF) and fat free mass (FFM) were assessed using a dual-energy x-ray absorptiometry scanner. Body weight was measured with an electronic scale, and height was assessed using a stadiometer. RESULTS: During the follow-up, swimmers presented higher gains in FFM (Control 2.35 kg vs. Swimming 5.14 kg; large effect size [eta-squared (ES-r)=0.168]) and BMD-Spine (Swimming 0.087 g/cm(2) vs. Control 0.049 g/cm(2); large effect size [ES-r=0.167]) compared to control group. Male swimmers gained more FFM (Male 10.63% vs. Female 3.39%) and BMD-Spine (Male 8.47% vs. Female 4.32%) than females. Longer participation in swimming negatively affected gains in upper limbs among males (r=-0.438 [-0.693 to -0.085]), and in spine among females (r=-0.651 [-0.908 to -0.036]). CONCLUSIONS: Over a 9-month follow-up, BMD and FFM gains were more evident in male swimmers, while longer engagement in swimming negatively affected BMD gains, independently of sex.

Basketball Affects Bone Mineral Density Accrual in Boys More Than Swimming and Other Impact Sports: 9-mo Follow-Up.

The objective of this study was to analyze the effect of different sports on bone mineral density (BMD) accrual among male adolescents during a 9-mo follow-up. The sample was composed of 82 boys (control [n = 13], basketball [n = 14], karate [n = 9], soccer [n = 18], judo [n = 12], and swimming [n = 16]) who were followed up for 9 mo (from October 2013 to August 2014). BMD (gram per square centimeter) was assessed at baseline and follow-up using a dual-energy X-ray absorptiometry scanner, whereas somatic maturation was estimated through the use of the peak height velocity. Vitamin D consumption was assessed by questionnaire. After 9 mo of follow-up, all groups (including the control group) presented significant BMD accrual (overall sample: 4.5% in the whole body). On the other hand, the basketball group presented higher BMD accrual in the upper limbs (17.6%) than the control group (7.2%). A similar difference was observed in whole-body BMD (control group: 4.1% vs basketball group: 7.1%). The basketball group had significantly higher BMD gains than the control group and other sports groups.

Prolonged Practice of Swimming Is Negatively Related to Bone Mineral Density Gains in Adolescents

BACKGROUND: The practice of swimming in "hypogravity" conditions has potential to decrease bone formation because it decreases the time engaged in weight-bearing activities usually observed in the daily activities of adolescents. Therefore, adolescents competing in national levels would be more exposed to these deleterious effects, because they are engaged in long routines of training during most part of the year. To analyze the effect of swimming on bone mineral density (BMD) gain among adolescents engaged in national level competitions during a 9-month period. METHODS: Fifty-five adolescents; the control group contained 29 adolescents and the swimming group was composed of 26 athletes. During the cohort study, BMD, body fat (BF) and fat free mass (FFM) were assessed using a dual-energy x-ray absorptiometry scanner. Body weight was measured with an electronic scale, and height was assessed using a stadiometer. RESULTS: During the follow-up, swimmers presented higher gains in FFM (Control 2.35 kg vs. Swimming 5.14 kg; large effect size [eta-squared (ES-r)=0.168]) and BMD-Spine (Swimming 0.087 g/cm² vs. Control 0.049 g/cm²; large effect size [ES-r=0.167]) compared to control group. Male swimmers gained more FFM (Male 10.63% vs. Female 3.39%) and BMD-Spine (Male 8.47% vs. Female 4.32%) than females. Longer participation in swimming negatively affected gains in upper limbs among males (r=-0.438 [-0.693 to -0.085]), and in spine among females (r=-0.651 [-0.908 to -0.036]). CONCLUSIONS: Over a 9-month follow-up, BMD and FFM gains were more evident in male swimmers, while longer engagement in swimming negatively affected BMD gains, independently of sex.